A new genetic editing technique has stopped the progression of a serious genetic disease in mice. The disease is the deficiency of ornithine transcarbamylase, a disease caused by hundreds of mutations in the same gene. Thanks to CRISPR, Penn Medicine scientists have developed a possible effective therapy on all mutations.
The authors of the study had already made an attempt at genetic therapy, but had managed to correct only one mutation. The approach had proven effective in newborn guinea pigs, but not in adults. This time, they developed a technique that inserts a mini-gene into the genome. The gene contains the correct information on how to code for the enzyme, in order to overwrite the wrong ones.
The new approach is effective on both puppies and adults. Above all, it is more effective than traditional cut and paste. In contrast to this, in fact, it manages to counteract a large number of mutations together. In this way, the organism resumes producing the enzyme and supporting it with the features that, without editing, would remain silent. The approach has proven effective on guinea pigs; scientists are working on the application on humans.
The CRISPR variant uses a virus that acts as a vector. Inside there is a small portion of gene that is added to the material already present. Formally speaking, the technique does not correct the mutation; rather, it overwrites it with more relevant genetic material. The genes that prevent the production of the ornithine transcarbamylase enzyme remain, but there are others that promote it.